Ataxic hemiparesis with reductions of ipsilateral cerebellar blood flow.

Abstract

SUMMARY Regional cerebellar blood flow was measured in a patient with left-sided ataxic hemiparesis, using single-photon emission computed tomography and N-isopropyl-p-[1Z3 I]Iodoamphetamine. X-ray computed tomography revealed a small infarct in the paramedian portion of the right upper basis pontis. Blood flow was markedly reduced in the contralateral cerebellar hemisphere corresponding to the side of ataxia. The present study emphasizes the value of the three-dimensional functional imaging of the cerebellum to Investigate the responsible lesion for ataxia and to study function of the cerebro-cerebellar circuits. Stroke Vol 17, No 5, 1986 IN 1978, Fisher 1 reported a pathological study of three patients with sudden onset of weakness and cerebellar ataxia of the same side. He suggested that this unusual combination of ipsilateral hemiparesis and ataxia is caused by a lacunar infarct in the upper basis pontis, and he proposed that the designation "ataxic hemiparesis" should be used to supplant the previously designated "homolateral ataxia with crural paresis" which he himself reported in 1967.2 In subsequently reported cases of ataxic hemiparesis, however, the location of CT lesions were rather diverse including not only the basis pontis 3 but also the internal capsule/ 5 corona radiata 6 and midbrain. 7 Based on these variable localizations of CT lesions, some authors 89 speculate that there are several regions where a small lesion may damage both the pyramidal tract and the cerebro-cerebellar circuit. However, it has been a difficult question to settle whether the ataxia or dysmetria on the side of weakness is actually due to cerebellar dysfunction.We report a case of ataxic hemiparesis in which a lacunar infarct was confirmed in the basis pontis by CT scan and the reduction of contralateral cerebellar blood flow was measured by single-photon emission computed tomography and N-isopropyl-p-[123 I]Iodoamphetamine. Report of a CaseA 70-year-old, right handed, diabetic woman experienced three episodes of transient and mild weakness of the left arm and leg for two days prior to admission. The first episode was associated with slurred speech and the third with nausea. She was able to walk but tended to fall to the left. On the day of admission, she From the Departments of Medicine, and Radiology,* School of Medicine, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa-ken 228, Japan.Nihon Medi-Physics Co., Ltd. in Japan provided the N-isopropylp[123 I]Iodoamphetamine. Address correspondence to: Fumihiko Sakai, M.D., Department of Medicine, School of Medicine, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa-ken 228, Japan.Received September 4, 1985; accepted November 22, 1985. woke unable to walk without falling and there was severe clumsiness of the left arm. On examination she was alert, oriented, with intact recent and remote memory, and was not aphasic. Her blood pressure was 166/92 mmHg, and the pulse was 76/min and regular. She was moderately dysarthric with mild weakness of the left lowe...

Ipsilateral Cerebellar Diaschisis following Pontine Infarction

“…In contrast to previously reported cases of brain stem lacunar syndromes which both found decreased cerebel lar blood flow contralateral to the infarct and ipsilateral to the clinical deficit [8,9], we have no evidence to sug gest the right cerebellum was affected. This suggests a lesion sufficiently discrete to avoid damaging the CPC tract to the right cerebellum.…”

Effects of capsular or thalamic stroke on metabolism in the cortex and cerebellum: a positron tomography study.

“…This association has been reported in one patient with an internal capsule (posterior limb) infarct 19 and in another with a pontine infarct. 20 However, only one of our two patients with ataxic hemiparesis (contrasted to two of the four without ataxia) had significant CCH (ataxia could not be evaluated in severely hemiparetic patients). A specifically designed study is required to resolve this issue.…”

Pathophysiology of Acute Cerebral Ischemia: PET Studies in Humans

“…The clinical correlates, if any, of CCH remain as yet unsettled. A co-occurrence of CCH and ipsilateral ataxia has been anecdotically reported in two patients [31,32] but was not confirmed by Pappata et al [33].…”